[lxc-users] Cannot start container when lxc.cgroup.memory.* in config

[phep]

Hi,

My host machine is an (admittedly) ageing Athlon AMD Athlon(TM) XP 2200+ on 
an Asustek A7V8X-X MB. RAM is 1.5 G big and the swap partition is 3 Go. The 
box is running a freshly updated Debian wheezy 7.4.

The host fstab has the following line :
cgroup          /sys/fs/cgroup  cgroup  defaults        0       0

The mount command displays this for cgroup :

cgroup on /sys/fs/cgroup type cgroup 
(rw,relatime,perf_event,blkio,net_cls,freezer,devices,cpuacct,cpu,cpuset,clone_children)

lxc-checkconfig displays :
Kernel config /proc/config.gz not found, looking in other places...
Found kernel config file /boot/config-3.2.0-4-686-pae
--- Namespaces ---
Namespaces: enabled
Utsname namespace: enabled
Ipc namespace: enabled
Pid namespace: enabled
User namespace: enabled
Network namespace: enabled
Multiple /dev/pts instances: enabled

--- Control groups ---
Cgroup: enabled
Cgroup clone_children flag: enabled
Cgroup device: enabled
Cgroup sched: enabled
Cgroup cpu account: enabled
Cgroup memory controller: enabled
Cgroup cpuset: enabled

--- Misc ---
Veth pair device: enabled
Macvlan: enabled
Vlan: enabled
File capabilities: enabled


I lxc-created a wheezy debian container with no problem using the "debian" 
template.I first run the container a couple of times with the default basic 
configuration being only augmented in order to have a bridged veth interface 
with a static adress. Everything went fine, then.

My problem is that if I have any or both of the following two lines in the 
configuration file :

lxc.cgroup.memory.limit_in_bytes        = 500M
lxc.cgroup.memory.memsw.limit_in_bytes  = 3G

I cannot start the container anymore. This is what I get :

# lxc-start -n uc23 -f /var/lib/lxc/uc23/config
lxc-start: cgroup is not mounted
lxc-start: failed to setup the cgroups for 'uc23'
lxc-start: failed to setup the container
lxc-start: invalid sequence number 1. expected 2
lxc-start: failed to spawn 'uc23'
lxc-start: Device or resource busy - failed to remove cgroup 
'/sys/fs/cgroup//lxc/uc23'

After that /sys/fs/cgroup/lxc/uc23 is actually left in place until I restart 
the container (with the default configuration).

As soon as I comment off both lines, the container happily starts anew... :-/

Could it be the hardware is too old ?

I noticed that if I list the contents of /sys/fs/cgroup I cannot find any 
"memory" pseudo-directory.

I made some googling to no avail, alas, and would welcome any pointer...

TIA

phep